title: Multinational, observational study of procalcitonin in ICU patients with pneumonia requiring mechanical ventilation: a multicenter observational study.
abstract: BACKGROUND
  The intent of this study was to determine whether serum procalcitonin (PCT) levels are associated with prognosis, measured as organ dysfunctions and 28-day mortality, in patients with severe pneumonia.
  
  
  METHODS
  This was a multicenter, observational study of critically ill adult patients with pneumonia requiring mechanical ventilation conducted in 10 academic hospitals in Canada, the United States, and Central Europe. PCT was measured daily for 14 days using an immuno-luminometric assay.
  
  
  RESULTS
  We included 175 patients, 57 with community acquired pneumonia (CAP), 61 with ventilator associated pneumonia (VAP) and 57 with hospital acquired pneumonia (HAP). Initial PCT levels were higher in CAP than VAP patients (median (interquartile range: IQR); 2.4 (0.95 to 15.8) vs. 0.7 (0.3 to 2.15), ng/ml, P < 0.001) but not significantly different to HAP (2.2 (0.4 to 8.0) ng/ml). The 28-day ICU mortality rate for all patients was 18.3% with a median ICU length of stay of 16 days (range 1 to 142 days). PCT levels were higher in non-survivors than in survivors. Initial and maximum PCT levels correlated with maximum Sequential Organ Failure Assessment (SOFA) score r2 = 0.50 (95% CI: 0.38 to 0.61) and r² = 0.57 (0.46 to 0.66), respectively. Receiver operating curve (ROC) analysis on discrimination of 28-day mortality showed areas under the curve (AUC) of 0.74, 0.70, and 0.69 for maximum PCT, initial PCT, and Acute Physiology and Chronic Health Evaluation (APACHE) II score, respectively. The optimal cut-off to predict mortality for initial PCT was 1.1 ng/ml (odds ratio: OD 7.0 (95% CI 2.6 to 25.2)) and that for maximum PCT was 7.8 ng/ml (odds ratio 5.7 (95% CI 2.5 to 13.1)).
  
  
  CONCLUSIONS
  PCT is associated with the severity of illness in patients with severe pneumonia and appears to be a prognostic marker of morbidity and mortality comparable to the APACHE II score.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Erlanger Allee 101, 07747 Jena, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Bloos
authors.forename: John C
authors.initials: JC
authors.lastname: Marshall
authors.forename: Richard P
authors.initials: RP
authors.lastname: Dellinger
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
authors.forename: Guillermo
authors.initials: G
authors.lastname: Gutierrez
authors.forename: Emanuel
authors.initials: E
authors.lastname: Rivers
authors.forename: Robert A
authors.initials: RA
authors.lastname: Balk
authors.forename: Pierre-Francois
authors.initials: PF
authors.lastname: Laterre
authors.forename: Derek C
authors.initials: DC
authors.lastname: Angus
authors.forename: Konrad
authors.initials: K
authors.lastname: Reinhart
authors.forename: Frank M
authors.initials: FM
authors.lastname: Brunkhorst
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D002170:Canada / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000097:blood / Q000401:mortality / Q000628:therapy; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000097:blood* / Q000453:epidemiology / Q000401:mortality / Q000628:therapy*; D053717:Pneumonia, Ventilator-Associated / Q000097:blood / Q000401:mortality / Q000628:therapy; D011379:Prognosis; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012121:Respiration, Artificial; D018570:Risk Assessment / Q000379:methods; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide